There are a number of different circumstances in which it is necessary for a person to have an artificial airway placed in his or her respiratory tract. As used herein, the phrase xe2x80x9cartificial airwayxe2x80x9d includes devices such as tracheostomy tubes, endotracheal tubes, and the like. An artificial airway keeps the patient""s natural airway open so that adequate lung ventilation can be maintained.
In certain situations, the artificial airway must be left in the patient for a prolonged period of time. In these situations, it is critical that respiratory secretions be periodically removed from the patient""s respiratory tract. This is typically accomplished by the use of a respiratory suction catheter.
With conventional closed suction catheter assemblies, for example as set forth in U.S. Pat. Nos. 3,991,762 and 4,569,344, the catheter tube is enveloped by a protective sleeve. The catheter assembly includes a valve mechanism in communication with a vacuum source to control the suctioning process. At its distal or patient end, the closed suction catheter assembly is attached to the artificial airway via a manifold, connector, adaptor, or the like. When it is desired to remove secretions and mucous from the patient""s respiratory tract, the catheter tube is advanced through the protective sleeve and into the patient""s respiratory system through the artificial airway. Negative pressure is then applied to the proximal or clinician end of the catheter tube to evacuate the secretions and mucous. The tube is then withdrawn from the artificial airway and, as the catheter tube is pulled back into the protective sleeve, a wiper or seal strips or scrapes a substantial portion of any mucous or secretions from the outside of the catheter tube. However, the distal tip portion of the catheter tube does not pass through the seal or wiper and thus any secretions or mucous on the distal end must be removed by other means.
Some closed suction catheter assemblies typically include a lavage port for injecting a cleaning/lavage solution into a chamber at the distal end of the catheter assembly as suction is applied through the catheter tube for loosening and removing the secretions and mucous scraped from the exterior of the catheter tube. This procedure may be done with the catheter assembly attached to or removed from the artificial airway and the ventilation circuit.
In certain situations, the lavage injection and suctioning process may not adequately remove the secretions and mucous adhering to the distal tip of the catheter tube and the clinician may repeat the cleaning process a number of times in an attempt to clean the catheter tip. If the mucous and secretions accumulate or dry on the catheter tip, they can interfere with the suction efficiency of the catheter and necessitate premature replacement of the entire closed suction catheter assembly.
It may also be desired to remove any cleaning/lavage solution that may remain in the lavage chamber after the cleaning procedure before using the device again.
Thus, there is a need for a suction catheter assembly having a more efficient mechanism and method for adequately cleaning a catheter tube of a suction catheter assembly.
Objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
As used herein, the term xe2x80x9cdistalxe2x80x9d refers to the direction of the patient and the term xe2x80x9cproximalxe2x80x9d refers to the direction of the clinician.
The present invention relates to a method and apparatus for creating a turbulent fluid flow at an end of a tube having a distal opening and one or more side openings adjacent to the distal opening. It is believed that such a turbulent flow may have numerous beneficial applications in various fields in mixing procedures, cleaning procedures, etc. The invention has particular usefulness in the medical field. For example, in one particularly well suited application of the invention, the turbulent flow significantly enhances cleaning of the distal end portion of a suction catheter. It is also contemplated that the turbulent flow may be useful in other applications, including mixing, heating, or cooling solutions. It should thus be appreciated that the present method and apparatus are not limited to any particular type or configuration of medical device or intended use.
The method includes disposing the distal end portion of the medical tube in a closed chamber having a first orifice defined therethrough. The orifice is disposed in the chamber so as to be generally opposite from the tube. A liquid, such as a lavage or cleaning solution, is introduced into the chamber. The liquid is drawn into the distal opening in the tube, for example by applying a suction through the tube. As the liquid is drawn into the distal opening, another fluid medium, such as air, is drawn into the chamber through the first orifice. Applicants believe that a flow pattern is established wherein the fluid medium is drawn through the orifice and into the distal opening in the tube with the liquid. A portion of the fluid/liquid mixture drawn into the tube is conveyed out the side opening(s) in the tube, and back into the distal opening in the tube. This flow pattern may create a turbulence in the lavage or cleaning solution within the chamber, particularly around the circumference of the tube and within the distal end portion of the tube. It has been found that this turbulence creates a significant advantage in cleaning the distal end portion of the tube. For example, in an embodiment wherein the medical tube is a suction catheter tube, the turbulent air flow assists in breaking up conglomerations of mucous and secretions which the lavage/cleaning solution alone may not.
In the embodiment wherein the medical device tube is a catheter tube, particularly a suction catheter tube, the distal end portion of the tube may be withdrawn into a distal fitting such as an adaptor or manifold housing of the respective catheter assembly. xe2x80x9cFittingxe2x80x9d is a relatively broad term used to encompass any structure located at the distal end of the catheter assembly through which the catheter tube is withdrawn and includes, for example, any configuration of adaptor, connector, manifold, extension, etc. The fitting thus defines at least in part a portion of the closed chamber. The closed chamber may be considered as a cleaning chamber.
Once the distal end portion of the catheter tube is withdrawn into the fitting, a cover member is used to close off or seal the cleaning chamber. The first orifice may be defined through this cover member.
In one embodiment, the fitting may comprise an adaptor having a port that is detachable from a patient""s artificial airway, such as a tracheostomy tube, endotracheal tube, and the like. In this embodiment, the cover member may be a component separate from the adaptor that is configured to then be attached to the adaptor to close off the port once the distal end portion of the catheter tube has been withdrawn into the adaptor. The cover member cooperates with the adaptor to define the cleaning chamber in which the distal end portion of the catheter tube is disposed.
In an alternate embodiment, the cover member may be connected to and disposed within the fitting, particularly in the adaptor embodiment of the invention. The catheter tube is withdrawn into the adaptor past the cover member which then moves automatically to a sealing position once the distal end of the catheter tube has passed the cover member. For example, in this embodiment, the cover member may comprise a hinged flap member that moves into a position generally opposite from the distal end of the catheter tube once the catheter tube has been withdrawn past the flap member.
Once the distal end portion of the catheter tube is properly located within the cleaning chamber and the cover member has been positioned so that the first orifice is generally opposite from the distal opening in the tube, the turbulent flow process is initiated as described above. In the embodiment of the invention wherein the catheter tube is a respiratory suction catheter, suction is applied at the proximal end of the tube to draw the cleaning solution into the tube. This suction also establishes a vacuum condition within the cleaning chamber resulting in air being drawn through the first orifice into the cover member. In an alternate embodiment, the air introduced through the first orifice may be pressurized air.
In a cleaning operation as described herein, it may be desired to remove any remaining cleaning solution from the cleaning chamber prior to reusing the respiratory suction catheter. The cleaning solution is typically removed by suctioning the solution from the chamber through the distal opening of the catheter tube. However, with relatively larger cleaning chambers, it is possible that not all of the cleaning solution may be removed. Accordingly, the method and apparatus according to the invention may include additional steps and structure to ensure adequate removal of the cleaning solution from the cleaning chamber.
In one embodiment, additional orifices or holes are defined in the cleaning chamber and are disposed so as to direct the fluid medium, such as air, into the cleaning chamber at an angle and orientation so as to urge the lavage/cleaning solution away from the sides of the cleaning chamber and towards the distal opening in the catheter tube. After air is drawn through the first orifice for a period of time sufficient for cleaning the distal end portion of the catheter tube, the air or other fluid medium is then introduced through the additional orifices. In one embodiment, the additional orifices are a ring of orifices disposed around the first orifice. The additional orifices are covered by a separate cover device or cap.
The invention will be described in greater detail below with reference to various embodiments depicted in the figures.